Process of preparing cellulose for artificial silk.



s ratrrzs Parana. cl nics.

GEORGE L. SCHAEFER, OF NEW YORK, N. Y., AND AUGUST ISCHAEFER, OF BASEL,

SWITZERLAND.

' PROCESS OF IREPARYNG GELL'ULSE FUR ARTIFICIAL SILK.

' 4 Specification of Letters Extent.

@a'ten'ted Feb. 18,

Application filed June 5| 1907- Sarisl llo. 9177;477-

To all whom it may concern:

Be it known that we, Gnomes l4. SCHAE- run, a citizen of the United States residing in New York, in the borough of roolrlyn, county of Kings, and State of New York, and AUeUsT ScnAarnn, a citizen of the Empire of Germany, residing in Basel, in the Confederation .ol Switzerland, have invented certain 'newiand useful lm rovements in Processes of Pro aring Cell" use for Artificial Silk, of whic the following is aspecification.

It he. pens frequently in the manufacture of artificial silk and horsehair from cellulose that satisfactory clear and easily-flowing solutions of big concentration and free liquidity cannot be obtained with reliable anduniform certainty. Especially is this the case when cell ose dissolved in an ammoniacal solution: oi'cupric hydroxid is employed, so that 'in i'imny cases no useful result-is obtained.

We have discovered solution of cupric h droxid when prepared under certain conditions, Will fully meet the requirements of a solution for cellulose when the cellulose is submitted to a preparatory treatment whereby its solubility is not only. considerably increased, but an absolutely clear and freely-flowing solution ob tained. I y Y For this purpdse the invention consists of a process of' treat ng the cellulose reparatory to dissolving the same in the so vent as will be fully described hereinafter and finally pointed out in the claims. I

In carrying out our invention liters of Water are mixed with 30. kilograms of sodium carbonate and 40 liters ofcaustic potash of 24 Be. and heated under continuous 1 stirring at a temperature of from 50 to C.

in an open iron vessel which is heated by means of a steam-coil that is placed in the same or by means of a steam-pipe which deliners steam into the solution. To this mixture 5 liters of tar benzin are added under continuous stirring until a uniform mixture is obtained. The liquor thus obtained is transferred into a jacketed boiler which is'ti htl closed by a suitable cover,

and in Whic the cellulose has been placed. T he quantity of liquor in the boiler has to cover entirely the cellulose placed in the same. 2 liters of tar benzin are then added To the liquor and the mixture is then boiled that an ammoniacalunder continuous stirring by steam to the boiler at a pressure of about one atmosphere and a temperature corresponding to this pressure. The

continued ifcr about two hours.

can the boiling, the solution is washed with a considerable quantity of water, after which the excess of Water isscparated from the cellulose in a centrifugal machine, after which it is subjected for several hours to the bleaching action of a weak solution of hydrogen pcroriid. The cellulose is then again Washed with a considerable quantity of are l tor, then again separated from thewaterby centrifugal force, and then placed in a diluted sulfuric acid bath. Af er this the cellulose is again separated from the excess of liquid so as to form a somewhat brittle quality, and then again subjected for a short'timc to the bleaching action of a diluted solution'o f hy drogcn peroxid. The bleached cellulose, is seam. washed with a considerable quantity s v i h p oi ater, next freed from the excess of water:

by centrifugal force, and then placed in wet state into an ammoniacal solution of cupric hydroxid.

The cellulose can also be treated in the following manner: The cellulose is separated from the excess of water after being boiled i as before described and is then placed into a very diluted bath of hydrochloric acid,. after which it is separated from the surplus-" 1 liquid and treated with a diluted solution of hydrogen peroxid, then dried up to a cert degree, so that it contains about 20%,:01 water, then chopped or torn into small pieces by a suitable machine, after which it is ma for dissolution.

Cellulose prepared in the. foregoing manned easily dissolved by the solvent, formsf'a' clear solution and gives very good,

able results. 0

Having thus described our invention, we: claim as new and desireto secure by. Let rs- Patent: 1

1. The process herein described of pre ar ing cellulose for makin artificial silkgqw 'c'lo; consists in subjecting the cellulose ato high temperature and a pressure of about one" atmosphere successively to the action ore weak alkaline liquor and tar benzin, then to a diluted acid, and lastly to hydrogen per- OX1 i 2. The process herein described of treating cellulose preparatoryto dissolving the same for nmking artificial silk, which consists in I the surplus water therefronyand then bleach boiling the cellulose in a weak solution of I sodium carbonate, :1 caustic alkali and tar benzin under a pressure of about one atmosphere and a correspondingly high temperature, then tr'eating it with diluted sulfuric acid, and finally bleaching it with hydrogen peroxid. I l v 3. The process of treating, cellulose preparator to dissolving the same 'for making crtificia silk, which consists in boiling the cellulose under pressure and at a. correspondingly high temperature in a solution of sodium carbonate, caustic alkali and tar benzin, then washmg the same, next sub ecting it to the action 01 a diluted acid, again separating.

ing the some with l'iydrogen peroxid.

in testimony, that we claim the foregoing,

as our invention, we have signed our names 20 in presence of two subscribing Witnesses.

GEORGE L. SCHAEFE'R" AUGUST SCHAEFER;

Witnesses to the signature of George L. Schaefor:

PAUL GOEPEL, HEXRY J. SUH'RBIER. VVitnessrs to the signature of August Schaefor:

I Aoom'n -FIS01-IER, ARTHUR SOHWABZ. 

